The Eurocopter SA 365/AS365 Dauphin 2 (Dolphin) is a medium-weight multipurpose twin-engine helicopter currently produced by Airbus Helicopters. It was originally developed and manufactured by French firm Aérospatiale, which was merged into the multinational Eurocopter company during the 1990s. Since entering production in 1975, the type has been in continuous production for more than 40 years. The intended successor to the Dauphin is the Airbus Helicopters H160, which is yet to enter operational service as of March 2015.[1]

The Dauphin 2 shares many similarities with the Aérospatiale SA 360, a commercially-unsuccessful single-engine helicopter; however the twin-engine Dauphin 2 did meet with customer demands and has been operated by a wide variety of civil and military operators. Since the type's introduction in the 1970s, several major variations and specialised versions of the Dauphin 2 have been developed and entered production, including the military-oriented Eurocopter Panther, the air-sea rescue HH/MH-65 Dolphin, the Chinese-manufactured Harbin Z-9 and the modernised Eurocopter EC155.

This twin-engined version of the Dauphin, designated as the Dauphin 2, was announced in early 1973. The first flight of the first prototype took place on 24 January 1975, with production model deliveries starting in December 1978. In comparison with the earlier model, the SA 365 C featured twin 470 kW (630 shp) Arriel 1 turboshafts in a new engine fairing, a Starflex main rotor hub and a higher maximum take-off weight (3,400 kg or 7,495 lb). The aircraft's Fenestron anti-torque device featured 13 metal blades. Production of both the SA 360 and SA 365 C ceased in 1981, by which time approximately 40 SA 360s and 50 SA 365 C/C1s had been built. Both types were replaced by the SA 365 N.

SA 365 C1

Minor upgrade of the SA 365 C powered by Arriel 1A1.

AS365 N (originally SA 365 N)

This is a much improved version of the SA 365 C Dauphin 2, the first prototype flying on 31 March 1979. This version introduced the uprated 492 kW (660 shp) Arriel 1C turboshafts, a retractable tricycle undercarriage, enlarged tail surfaces, and revised transmission, main rotor, rotor mast fairing and engine cowlings. The aircraft's initial M.T.O.W. of 3,850 kg (8,490 lb) was later raised to 4,000 kg (8,800 lb). Deliveries of the production model began in 1982. As of 2014[update], it holds the speed record for a 3 km course, set at 372 km/h in 1991.[2]

This version – designated AS365 N2 from the outset – introduced the upgraded 549 kW (737 shp) Arriel 1C2 turboshafts, an uprated gearbox, increased maximum take-off weight of 4,250 kg (9,370 lb), redesigned cabin doors and revised interior, enlarged tail fin with all composite Fenestron. Deliveries of this version started in 1990. Licensed versions, called the Z-9 and Z-9A, were assembled in China.

AS365 N3

The high-performance AS365 N3 was developed for operations in 'hot and high' climates, and introduced 635 kW (851 shp) Arriel 2C turboshafts equipped with a single channel DECU (Digital Engine Control Unit) with manual reversion, mated to an uprated main transmission for better single engine performance. The AS365 N3 also features a redesigned ten blade composite Fenestron anti-torque device with asymmetric blade distribution, offering a further reduction in noise signature. The AS365 N3's gross weight is 4,300 kg (9,500 lb). Production deliveries began in December 1998 and this version is currently still in production.

Better known as the DGV 200 or Dauphin Grand Vitesse (High Speed Dauphin), the AS365 X was developed from the X-380 DTP (Developpement Technique Probatoire or Probatory Technical Development) testbed, first flown on 20 March 1989. The aircraft was first flown in the AS365 X configuration two years later in March 1991, and featured a smaller Fenestron, a new main rotor with five high-inertia blades with swept tips, a composite rotor hub/mast and 624 kW (837 shp) Turbomeca Arriel IX turboshafts. On 19 November 1991, this aircraft set a Class E1e (3,000 to 4,500 kg) speed record of 201 knots (372 km/h; 231 mph) over a 3 km triangular course.

This version was originally to follow the N3 as the AS365 N4, and was announced at the 1997 Paris Airshow before being redesignated as the EC155 B. As with the N3 version, it has two Arriel 2C/2C2 turboshafts equipped with FADEC as well as a five blade Spheriflex main rotor (derived from the AS365 X DGV). It also features a 30% larger main cabin (achieved with bulged doors and cabin plugs). The first flight of the first prototype took place on 17 June 1997 and this version is currently in production (as the EC155 B1).

The SA 366 G1 Dauphin version was selected by the United States Coast Guard (USCG) in 1979 as its new air-sea rescue helicopter and given the designation HH-65A Dolphin. In total 99 helicopters, optimised for the USCG's short-range recovery (SRR) search and rescue role, were initially acquired, with additional aircraft later procured.